Brush holder for dynamoelectric machines



Patented Oct. 20, 1942 BRUSH HOLDER FOR DYNAMOELECTRIC MACHFN Alfred E. Buerosse, Wauwatosa, Wis., assignor of two-thirds to George J. Buerosse, Beaver Dam,

Wis.

Application June 25, 1941, Serial No. 399,584

7 Claims.

This invention relates to brush holders for dynamoelectric machines and is an improvement over the brush holder illustrated in the Patent No. 2,205,464, issued to George J. Buerosse and Alfred E. Buerosse, June 25, 1940.

In the aforesaid patent the support and mounting for the receptacle, which directly receives the brush, is such that the receptacle is biased toward the commutator or other rotating part against which the brush bears with a spring tension guided by mechanical linkage.

The manner in which the brush receptacle is mounted in the present invention is along the same lines, the improvement residing in the means employed to hold the brush in its receptacle.

In the past it has been customary to provide some form of clamping arrangement for locking the brush to or in its receptacle. This generally required the use of tools in replacing the brush and also entailed the objectionable possibility of having the brush work loose during operation of the machine.

It is, therefore, an object of this invention to provide a more eflicient manner of securing the brush in its receptacle which not only permits immediate removal and replacement of the brush entirely without the use of tools, but is so designed that the brush cannot become loose in its receptacle during operation of the machine.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed in accordance with the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a side view of a brush holder embodying this invention; and

Figure 2 is a perspective view thereof shown detached from the machine.

Referring now particularly to the aocompanying drawing in which like numerals indicate like parts, the numeral 5 indicates the commutator or other rotating part of a dynamoelectric machine against which one or more brushes 6 are pressed.

In the embodiment of the invention here illustrated, two brushes are supported on opposite sides of a supporting arm I which extends radially from the axis of the dynamoelectric machine and has a stud 8 projected therefrom on which a brush holder indicated generally by the numeral 9 is fastened.

The brush holder comprises a stationary head or body In which is clamped to the stud 8 and a floating or movable head ll, one for each brush.

The number of brushes for which the holder is designed is immaterial as this merely involves duplication.

Each floating or movable head H is connected with the stationary head 9 by a pair of links l2 and a relatively stiff coil spring l3 acts on the head H to bias the same towards the commutator.

The actual brush receptacle of each floating head consists of a channel-shaped box-like unit l4 having a bottom wall [5 overlying the head II and opposite side walls Hi. This box-like receptacle is preferably formed of sheet metal shaped to form and brazed or otherwise fixed to the floating head II, or the side walls l6 may constitute an integral part of the head H in which instance the bottom wall l5 would be merely a surface of the head H.

In any event, a U-shaped open channel is provided the width of which is such as to snugly receive the brush 6. The opposite side walls It have diagonal slots 11 which open to the edge of the side wall and to the bottom thereof to receive the projecting ends of a cross pin [8 embedded in the brush 6. The side walls of the receptacle lie fiat against the adjacent faces of the brush so that the projecting ends of the pin I 8' need not be long.

The angle of diagonal slots 11 is such that the downward or inward force imposed on the receptacle and reacted against by the brush bearing on the commutator firmly wedges the brush against the bottom Wall l5 of the receptacle and holds the same against dislodgement during operation of the machine.

Removal and replacement of the brush is readily effected by merely lifting the floating head against the spring tension whereupon the brush may be slipped out of its receptacle, and by the provision of sets of diagonal slots as shown, most of the total length of the brush may be utilized for as the brush wears it may be advanced in its holder by engaging the projections l8 with the lower or inner set of slots.

From the foregoing description taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art that this invention provides an exceedingly simple but efiective manner of quickly detachably and firmly holding or securing a brush in its receptacle.

What I claim as my invention is:

1. In a brush holder of the character described having a stationary head and a movable head biased to an operative position: a brush receptacle carried by the movable head and comprising two opposite side walls provided with opposed diagonal slots; a brush in said receptacle; and projections on the opposite faces of the brush engaged in said slots, the angle of said slots being such that the thrust imposed on the projections by the edges of the slots firmly lodges the brush in the receptacle.

2. In a brush holder for dynamoelectric machines: a box-like brush receptacle having opposed walls, at least one of said walls having a diagonal slot; a brush in the receptacle; and a projection on the brush engaged in said slot, the angle of the slot with relation to the longitudinal axis of the brush being such that application of pressure on the brush by the receptacle to hold the brush against the rotating part of the dynamoelectric machine firmly lodges the brush in the receptacle.

3. In a brush holder for dynamoelectric machines: a brush receptacle biased toward the rotating part of the machine upon which the brush bears, said receptacle comprising substantially an open channel having spaced side walls, at least one of said side walls having a diagonal slot; a brush in said receptacle; and a projection on the brush engaging in said slot, the slot being so inclined with relation to the longitudinal axis of the receptacle that the brush is wedged against the bottom of the receptacle and thus firmly held in place under the biasing force acting on the receptacle.

4. In a brush structure for dynamoelectric machines: a brush receptacle in the form of an open channel having opposite side walls; means supporting the receptacle and biasing the same toward a rotating part of the machine to press a brush held thereby against said rotating part; a brush readily removably fitted in the open channel with one edge thereof engaging the bottom of the channel and its opposite faces covered by the side walls of the channel; and cooperating means on the brush and at least one of said side walls for holding the brush in the receptacle, said means utilizing the bias on the receptacle to force the brush against the bottom of the channel and 5. In a brush structure fior dynamoelectric machines: a brush receptacle in the form of an open channel having opposite side walls; means supporting the receptacle and biasing the same toward a rotating part of the machine to press a brush held thereby against said rotating part; a brush readily removably fitted in the open channel with one edge thereof engaging the bottom of the channel and its opposite faces covered by the side walls of the channel; and a cross pin carried by the brush and projecting from opposite sides thereof, and said side walls of the receptacle having diagonal slots to receive the ends of the cross pin, said slots opening to the edges of the side walls and being inclined in such a direction that the biasing force on the receptacle wedges the brush against the bottom of the channel to firmly hold the same against dislodgement while permitting ready removal of the brush from the receptacle.

6. In a brush structure for dynamoelectric machines: a brush receptacle in the form of an open channel having opposite side walls; means supporting the receptacle and biasing the same toward a rotating part of the machine to press a brush held thereby against said rotating part; a brush readily removably fitted in the open channel with one edge thereof engaging the bottom of the channel and its opposite faces covered by the side walls of the channel; a cross pin in the brush with the ends thereof projecting from opposite sides of the brush; and a plurality of sets of diagonal slots in the side walls of the channelshaped receptacle opening to, the edges of the side walls to receive the projecting ends of the cross pin and holding the brush in a selected position of longitudinal adjustment in the receptacle, the angle of said diagonal slots with relation to the longitudinal axis of the receptacle being such that the bias imposed on therreceptacle firmly lodges the brush against the bottom of the channel.

'7. In a brush structure for dynamoelectric machines: a brush receptacle; means movably supporting the receptacle and biasing the same for movement in a direction to press a brushrcarried thereby against a rotating part of the dynamoelectric machine; a brush in said receptacle; and cooperating means on the receptacle and the brush for maintaining the brush firmly in position with respect to the receptacle in response to reaction of the brush against the biasing force on the receptacle and for enabling ready removal of the brush from the receptacle upon movement of the receptacle against its biasing force and to relieve the brush of said biasing force.

ALFRED E. BUEROSSE. 

